#include<stdio.h>
int main(void){
	int n,i=0,b;
	scanf("%d",&n);
	char a[55],ch;
	getchar();
	scanf("%c",&ch);
	while(ch!='\n'){
		a[i]=ch;
		i++;
		scanf("%c",&ch);
	}
	for(b=0;b<i;b++){
		if(a[b]<=122-n) a[b]=a[b]+n;
		else a[b]=a[b]+n-26;
		printf("%c",a[b]);
	}
	return 0;
}